Specificity of fungal associations of Pyroleae and Monotropa hypopitys during germination and seedling development

Mycoheterotrophic plants obtain organic carbon from associated mycorrhizal fungi, fully or partially. Angiosperms with this form of nutrition possess exceptionally small 'dust seeds' which after germination develop 'seedlings' that remain subterranean for several years, fully dependent on fungi for supply of carbon. Mycoheterotrophs which as adults have photosynthesis thus develop from full to partial mycoheterotrophy, or autotrophy, during ontogeny. Mycoheterotrophic plants may represent a gradient of variation in a parasitism-mutualism continuum, both among and within species. Previous studies on plant-fungal associations in mycoheterotrophs have focused on either germination or the adult life stages of the plant. Much less is known about the fungal associations during development of the subterranean seedlings. We investigated germination and seedling development and the diversity of fungi associated with germinating seeds and subterranean seedlings (juveniles) in five Monotropoideae ...菌异养植物（Mycoheterotrophic plants）可全部或部分从与其共生的菌根真菌（mycorrhizal fungi）处获取有机碳源。具备此种营养方式的被子植物（Angiosperms）会产生极为微小的“尘状种子”，种子萌发后形成的幼苗会在地下存活数年，完全依赖真菌提供碳源。成年后具备光合作用能力的菌异养植物，在个体发育（ontogeny）过程中会从完全菌异养逐步转变为部分菌异养，甚至转为自养。菌异养植物在物种种间和种内均可能呈现出寄生-共生连续体（parasitism-mutualism continuum）上的变异梯度。此前针对菌异养植物与真菌共生关系的研究，多聚焦于植物的萌发阶段或成年生活史阶段，而针对地下幼苗发育阶段的真菌共生关系，目前所知甚少。本研究针对5个水晶兰亚科（Monotropoideae）类群，对其种子萌发、幼苗发育过程，以及与萌发种子和地下幼苗（幼体）相关的真菌多样性展开了调查……